ValueEventListener

public interface ValueEventListener

Classes implementing this interface can be used to receive events about data changes at a location. Attach the listener to a location user addValueEventListener(ValueEventListener).

Public Method Summary

abstract void
onCancelled(DatabaseError error)
This method will be triggered in the event that this listener either failed at the server, or is removed as a result of the security and Firebase Database rules.
abstract void
onDataChange(DataSnapshot snapshot)
This method will be called with a snapshot of the data at this location.

Public Methods

public abstract void onCancelled (DatabaseError error)

This method will be triggered in the event that this listener either failed at the server, or is removed as a result of the security and Firebase Database rules. For more information on securing your data, see: Security Quickstart

Parameters
error A description of the error that occurred

public abstract void onDataChange (DataSnapshot snapshot)

This method will be called with a snapshot of the data at this location. It will also be called each time that data changes.

Parameters
snapshot The current data at the location

发送以下问题的反馈:

此网页
需要帮助?请访问我们的支持页面